In cooperation with the Department of Nuclear Medicine, and the Laboratory of Tumor Immunology and Biology, we have initiated clinical trials for the treatment of peritoneal carcinomatosis. A classical phase one study has begun using escalating doses of I- 131 labeled antibody administered intraperitoneally. We have treated a total of eight patients with therapeutic doses of antibody, the first two at 50 millicuries, the next three at 100 millicuries, and the last three at 125 millicuries. The first two patients were heavily pre-treated with chemotherapy. They showed no response to therapy and progressed. Two of the patients receiving the 100 millicurie dose also progressed. The third patient will soon be evaluated with repeat CT, and if negative, will undergo exploration of the abdomen to document disease status. The three patients treated with 125 millicuries are not yet evaluable. There has been minimal toxicity of the radiolabeled antibodies with two patients at the highest dose having abdominal cramps following the instillation of antibody, and one patient had suppression of her bone marrow causing Grade I toxicity in her PMN count, and Grade II toxicity of her platelet count. During the next year, we plan to treat additional patients at higher doses, and evaluate the use of different radioisotopes.